How to Improve Your LCP Score: A Step-by-Step Optimization Guide
Knowing your LCP score is slow is only half the battle. The real work is figuring out which fix will move the needle fastest. This guide walks through the most effective optimizations in the order most sites should tackle them.
Key takeaways:
- Image optimization delivers the fastest, most reliable LCP improvements for most sites
- Server response time (TTFB) sets a hard floor on how fast LCP can ever be
- Render-blocking CSS and JavaScript should be deferred or eliminated where possible
- Preloading your LCP element can shave meaningful time off render
- Fixes should be tested with field data, not just a single lab report
Start With the Biggest Wins
Not all fixes are equal. Optimizing a massive unoptimized hero image can cut seconds off your LCP in an afternoon, while fixing minor CSS delivery issues might save only milliseconds. Prioritize accordingly.
The Optimization Checklist
| Step | Action | Typical Impact |
|---|---|---|
| 1. Compress and resize images | Use modern formats (WebP/AVIF) and serve correctly sized images | High |
| 2. Improve server response time | Upgrade hosting, use a CDN, enable caching | High |
| 3. Eliminate render-blocking resources | Defer non-critical CSS/JS, inline critical CSS | Medium–High |
| 4. Preload the LCP element | Add <link rel="preload"> for hero images/fonts | Medium |
| 5. Remove unnecessary third-party scripts | Audit chat widgets, trackers, ad scripts | Medium |
| 6. Use a CDN | Serve assets from servers closer to visitors | Medium |
| 7. Avoid client-side rendering for above-the-fold content | Server-render or statically generate key content | Medium–High |
Why Order Matters
Fixing render-blocking scripts won't help much if your server itself takes three seconds to respond. Work top-down: server speed and image weight first, then rendering behavior, then smaller refinements like preloading. Doing them in this order avoids wasted effort on fixes that get overshadowed by bigger bottlenecks further down the pipeline.
Mistakes to Avoid While Optimizing
- Over-compressing images to the point of visible quality loss — aim for the smallest file size that still looks sharp.
- Preloading too many resources — preloading everything defeats the purpose and can actually slow down the true LCP element.
- Testing only on fast Wi-Fi — always check performance under throttled, mobile-like conditions, since that's closer to real visitor conditions.
- Fixing lab scores while ignoring field data — a great Lighthouse score doesn't guarantee real users are having a fast experience.
Frequently Asked Questions
How much can I realistically improve my LCP?
Many sites with unoptimized images can cut LCP by 40–60% just from compression and proper sizing, without any code changes.
Do I need a developer to fix LCP issues?
Basic image optimization can often be done through a CMS or plugin, but server-level and script-related fixes typically require developer involvement.
How long until I see the improvement reflected in Google's reports?
Search Console's Core Web Vitals report uses a rolling 28-day window of real user data, so it can take several weeks for improvements to fully show up there, even though tools like PageSpeed Insights reflect changes immediately.
Next Steps for Your Business
Pick your slowest page, work through the checklist above in order, and re-test after each major change so you know what actually moved the number.
Our development team can implement these optimizations for you and validate the results with real-world performance data.